The present invention relates to a new measurement and observation process for the characteristics of changing complex fluids from the start of their implementation to the end of their production. On the basis of these processes, certain phases of which are known, several devices, for which we will essentially give the two most interesting embodiments, will be designed.
Fluids referred to as complex such as: emulsion, gels, dilutions of different liquids, dispersions, etc. are frequently used in the agri-food industry, the beauty product industry, particularly in cosmetics, in the petroleum industry and in the chemical industry in general. The complexity of these fluids lies in the fact that their characterisation depends equally on the chemical composition, processing and preservation processes and many other parameters. In this way, the same chemical formulation does not enable:
The direct industrial reproduction of the laboratory formulation.
The industrial reproduction of identical products from different manufacturing batches.
The production of particles of a given size.
A guarantee that ageing (coalescence, decantation) will have a constant duration.
It is also very difficult to find out the emulsifying qualities of products, for example, in the case of:
An emulsifier bound to other compounds
A mixing geometry for a desired formulation.
Let us take the case of the food industry (e.g. mayonnaise). If we consider this type of emulsion, we obtain a probability of an unsatisfactory result (high failure rate), therefore unacceptable for industrial manufactures.
Let us take a second example in the case of the beauty product industry, a moisturising cream; for some batches, it is not possible to implement the manufacturing process to achieve the result, i.e. the preparation will not emulsify, resulting in unusable costly rejects.
To achieve a satisfactory result (reliability approaching 100%), it is necessary to characterise all the physical and chemical formulation parameters of the manufacturing processes. It is for this reason that the invention with measurement or monitoring devices adapted to these requirements has been proposed.
The documents of the prior art accessible to the public use known means which can improve the manufacturing processes of these complex fluids empirically. The numerous existing publications describe means which are rather measurement arrangements which improve the knowledge of complex fluids slightly without solving the formulation problems completely.
The specialist can currently use a certain number of monitoring and measurement tools; however, they do not enable him to predict the quality of the product, since this information is only fragmented and is not coordinated.
The main parameters (measurements and observations) essential for a correct complex fluid manufacturing procedure are:
1xe2x80x94Monitoring of the viscosity (the most frequently observed parameter)
2xe2x80x94Optical microscopy monitoring making it possible to identify the texture of the fluid, particularly the grain or particle size, either by sampling or in the presence of shearing forces.
3xe2x80x94A mean particle size measurement by diffusion of a radiation by a laboratory means (such as COUETTE cell) still, for example, under the effect of shearing, or by sampling and dilution
4xe2x80x94A dielectric conductivity measurement of the materials still during the formulation of the complex fluid
5xe2x80x94Turbidity monitoring by measuring the light intensity transmitted through the sample (case of sedimentation).
All these measurements are made with separate devices either by sampling, which disturbs the medium, or with devices with a single-function means which cannot reveal the exact state of the complex fluid.
1xe2x80x94Case of sampling
The disturbance of the medium induces a measurement not corresponding to the state of said medium for various reasons, difference in time, influence on medium, etc.
2xe2x80x94Case of a single xe2x80x9cin situxe2x80x9d measurement
One measurement or observation alone be used to characterise the entire complex fluid. All the parameters obtained show a great inconsistency with no correlation.
However, we will mention three documents which approach the problem to be solved, but do not solve it completely.
The SOUBIRAN publication in EUROPHYSICS LETTERS 31-4 pages 243 to 246 in 1995 describes a dielectric conductivity measurement geometry under shearing. However, it cannot be used to obtain a result that can be used industrially, since the measurement is restrictive and the acquisition cannot be exploited directly.
The U.S. Pat. No. 4,352,287A (ORTH HEINZ W ET AL) describes a computerised device making it possible to analyse the viscosity under shearing alone, a mechanical parameter that overall is for the characterisation of a complex fluid, under shearing in a precise way; it is a specific viscometer, the principle of which differs from that of the present invention.
The document WO 95 12122 (AGRONOMIQUE INST NAT RECH) is a device which only performs a conductivity measurement during the mixing of the complex fluid, which is insufficient to find out the variation.
To characterise in-process complex fluids well, it is possible to either analyse a single physical characteristic, e.g. the electric conductivity by obtaining the highest number of measurements related to this value, exhaustively, or analyse all the significant physical characteristics so as to establish the correlations between measurements and observations, resulting in the definition of two types of devices: the first more of the single-function type well-adapted to in-process monitoring, the second of the multi-function type making it possible to obtain a better characterisation of the formulation of complex fluids.
In the case of our invention: this new process P makes it possible to characterise and measure all the accessible parameters of the complex fluid with measurement and simultaneous characterisation operations performed on the same sample by
managing, at the same time, the control means in conjunction with the measurement means, thus by simultaneously displaying the data on a computer screen,
storing all the data in memory to be able to retrieve it at any time.
establishing and using correlations, particularly in relation to time, with said data which directly depends on the characteristics of the complex fluids to be managed, giving significant measurements making it possible to achieve industrial manufactures. This process will then consist of comparing the analysis results obtained previously on the fluids simultaneously to the in-process results obtained, in order to deduce the correlations making it possible to predict the variation of the complex fluid manufacture. The present invention fulfils these requirements in two embodiments of devices depending on the above process, which will now be described in succession, in two non-restrictive examples of embodiments.